In this paper, we discuss the influence of ratio of minor to major axis on the propagation property and focusing performance of a plasmonic lens with variant periodic concentric elliptical slits illuminating under a G...In this paper, we discuss the influence of ratio of minor to major axis on the propagation property and focusing performance of a plasmonic lens with variant periodic concentric elliptical slits illuminating under a Gaussian beam. In order to analyse the influence theoretically, a finite-difference time-domain （FDTD） numerical algorithm is adopted for the computational numerical calculation and the design of the plasmonic structure. The structure is flanked with penetrated slits through a 200-nm metal film （Au） which is coated on a quartz substrate. Tunability of focusing capability of the plasmonic lenses is studied by tailoring the ratio. Our calculation results demonstrate that the ratio of the elliptical slits greatly affects the focusing capability of the lense. The plasmonic lenses with concentric elliptical slits illuminating under a Gaussian beam have ultra-elongated depth of focus. These results are very encouraging for the future study of the plasmonic lens-based applications.展开更多
<strong>Purpose:</strong> To clinically evaluate a new extended depth of focus intraocular lens (ISOPURE, PhysIOL) with optic design modification based on a unique polynomial concept to improve intermediat...<strong>Purpose:</strong> To clinically evaluate a new extended depth of focus intraocular lens (ISOPURE, PhysIOL) with optic design modification based on a unique polynomial concept to improve intermediate vision while keeping the quality of distance vision equal to a monofocal lens. <strong>Methods:</strong> 18 patients (11 female, 7 male, mean age of 69.4 years) with bilateral cataract and regular corneal astigmatism ≤ 1.0 D underwent bilateral cataract surgery with ISOPURE implantation. Patients were followed for up to 6 months. Measured parameters were uncorrected (UDVA) and corrected distance visual acuity (CDVA), uncorrected (UIVA) and distance-corrected intermediate visual acuity at 80 cm and 66 cm (DCI80VA, DCI66VA) subjective refraction, defocus curve, tolerance of cylinder induction, and contrast sensitivity. The data from all implanted eyes (all-eyes) and a subset only including the first eye implanted for each patient were analysed. <strong>Results:</strong> The mean manifest refraction spherical equivalent (MRSE) decreased from 1.05 D pre-operatively to ?0.15 D at the 4 - 6 month assessment, with 80.6% of eyes within ±0.50 D of emmetropia. At the final follow-up, mean (SD) monocular CDVA was ?0.06 (0.04) logMAR, DCI80VA was 0.18 (0.08) logMAR and DCI66VA was 0.27 (0.13) logMAR. Despite a cylinder induction of ?0.50 D, uncorrected distance visual acuity of 0.02 logMAR was still achieved. <strong>Conclusion:</strong> The ISOPURE intraocular lens provides excellent distance corrected visual acuity for far and intermediate distances along with high contrast sensitivity and good tolerance of residual refractive cylinder.展开更多
The damage properties of Focused Ion Beam(FIB) milling Si3N4 thin film are investigated by the detailed analyzing images of nanoholes and simulation of Monte Carlo. The damage depth in the Si3N4 thin film for two diff...The damage properties of Focused Ion Beam(FIB) milling Si3N4 thin film are investigated by the detailed analyzing images of nanoholes and simulation of Monte Carlo. The damage depth in the Si3N4 thin film for two different ion species(Gallium and Arsenic) under various parameters(ion energy, angle of incidence) are investigated by Monte Carlo method. The simulations show the damage depth increases with the increasing ion energy, the damage depth is dependent on the angle of incident ion, the curves of the damage depth for Ga ion and As ion at 30 keV nearly superpose, while the damage depth for Ga with 90 keV ion is more than that for As ion with the same energy.展开更多
Gaussian beam migration （GBM） is an effec- tive and robust depth seismic imaging method, which overcomes the disadvantage of Kirchhoff migration in imaging multiple arrivals and has no steep-dip limitation of one-wa...Gaussian beam migration （GBM） is an effec- tive and robust depth seismic imaging method, which overcomes the disadvantage of Kirchhoff migration in imaging multiple arrivals and has no steep-dip limitation of one-way wave equation migration. However, its imaging quality depends on the initial beam parameters, which can make the beam width increase and wave-front spread with the propagation of the central ray, resulting in poor migration accuracy at depth, especially for exploration areas with complex geological structures. To address this problem, we present an adaptive focused beam method for shot-domain prestack depth migration. Using the infor- mation of the input smooth velocity field, we first derive an adaptive focused parameter, which makes a seismic beam focused along the whole central ray to enhance the wave- field construction accuracy in both the shallow and deep regions. Then we introduce this parameter into the GBM, which not only improves imaging quality of deep reflectors but also makes the shallow small-scale geological struc- tures well-defined. As well, using the amplitude-preserved extrapolation operator and deconvolution imaging condi- tion, the concept of amplitude-preserved imaging has been included in our method. Typical numerical examples and the field data processing results demonstrate the validity and adaptability of our method.展开更多
Background:Enhanced depth-of-focus intraocular lenses(EDOF IOL)have filled the gap between monofocal and multifocal intraocular implants with optical qualities of monofocal lenses and usually minor dysphotopsias typic...Background:Enhanced depth-of-focus intraocular lenses(EDOF IOL)have filled the gap between monofocal and multifocal intraocular implants with optical qualities of monofocal lenses and usually minor dysphotopsias typical for multifocal lenses.The purpose of this study was to evaluate visual outcomes after bilateral implantation of a new EDOF IOL in patients with requirements for perfect near and intermediate vision.Methods:The study included 15 patients(29 eyes as one was amblyopic)with bilateral implantation of LUXSMART EDOF IOL(Bausch&Lomb)with a targeted myopia(between-0.25 and-0.50D)in both eyes.Monocular corrected and uncorrected visual acuity for far,intermediate and near as well as refractive outcomes were evaluated at 1,3,6 and 12 months after the surgery.Additionally,binocular visual acuity,contrast sensitivity and defocus curve were measured at the final follow-up visit.At 12 months’visit patients completed a questionnaire evaluating patient satisfaction,spectacle independence and presence of dysphotopsias.Results:Binocular uncorrected visual acuities at 12 month’s visit were 0.13±0.16,0.06±0.08,0.07±0.09 and 0.15±0.09 logMAR for far distance,80 cm,66 cm and 40 cm respectively.Corrected binocular visual acuities at 12 months were 0.00±0.00,0.05±0.07,0.05±0.06,0.13±0.16 respectively for distance,80 cm,66 cm and 40 cm.Automated refraction spherical equivalent at 12 months’visit stood at-0.70±0.48D,which was 0.46D less than calculated biometric target,however spherical equivalent of subjective refraction at 12 months equaled–0.49±0.46D,which was closer to preoperative biometric target.Defocus curve had gentle shape without peaks typical for monofocal IOLs.Binocular contrast sensitivity results were superior to average results for that age group and equaled 1.78±0.16 logMAR without correction and 1.81±0.13 logMAR with correction.Spectacle independence for near and intermediate distances was achieved in all patients and for far distance in 73.3%of patients.Burdensome dysphotopsias were not reported in any case.Conclusions:EDOF IOLs targeted bilaterally at low myopia can provide excellent near and intermediate visual acuity and independence of any optical correction in majority of cases.This approach can be used in selected patients who are focused on stationary activities.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11079014 and 61077010)
文摘In this paper, we discuss the influence of ratio of minor to major axis on the propagation property and focusing performance of a plasmonic lens with variant periodic concentric elliptical slits illuminating under a Gaussian beam. In order to analyse the influence theoretically, a finite-difference time-domain （FDTD） numerical algorithm is adopted for the computational numerical calculation and the design of the plasmonic structure. The structure is flanked with penetrated slits through a 200-nm metal film （Au） which is coated on a quartz substrate. Tunability of focusing capability of the plasmonic lenses is studied by tailoring the ratio. Our calculation results demonstrate that the ratio of the elliptical slits greatly affects the focusing capability of the lense. The plasmonic lenses with concentric elliptical slits illuminating under a Gaussian beam have ultra-elongated depth of focus. These results are very encouraging for the future study of the plasmonic lens-based applications.
文摘<strong>Purpose:</strong> To clinically evaluate a new extended depth of focus intraocular lens (ISOPURE, PhysIOL) with optic design modification based on a unique polynomial concept to improve intermediate vision while keeping the quality of distance vision equal to a monofocal lens. <strong>Methods:</strong> 18 patients (11 female, 7 male, mean age of 69.4 years) with bilateral cataract and regular corneal astigmatism ≤ 1.0 D underwent bilateral cataract surgery with ISOPURE implantation. Patients were followed for up to 6 months. Measured parameters were uncorrected (UDVA) and corrected distance visual acuity (CDVA), uncorrected (UIVA) and distance-corrected intermediate visual acuity at 80 cm and 66 cm (DCI80VA, DCI66VA) subjective refraction, defocus curve, tolerance of cylinder induction, and contrast sensitivity. The data from all implanted eyes (all-eyes) and a subset only including the first eye implanted for each patient were analysed. <strong>Results:</strong> The mean manifest refraction spherical equivalent (MRSE) decreased from 1.05 D pre-operatively to ?0.15 D at the 4 - 6 month assessment, with 80.6% of eyes within ±0.50 D of emmetropia. At the final follow-up, mean (SD) monocular CDVA was ?0.06 (0.04) logMAR, DCI80VA was 0.18 (0.08) logMAR and DCI66VA was 0.27 (0.13) logMAR. Despite a cylinder induction of ?0.50 D, uncorrected distance visual acuity of 0.02 logMAR was still achieved. <strong>Conclusion:</strong> The ISOPURE intraocular lens provides excellent distance corrected visual acuity for far and intermediate distances along with high contrast sensitivity and good tolerance of residual refractive cylinder.
基金Science Foundation of Yunnan Province , China(2004A00229 M)
文摘The damage properties of Focused Ion Beam(FIB) milling Si3N4 thin film are investigated by the detailed analyzing images of nanoholes and simulation of Monte Carlo. The damage depth in the Si3N4 thin film for two different ion species(Gallium and Arsenic) under various parameters(ion energy, angle of incidence) are investigated by Monte Carlo method. The simulations show the damage depth increases with the increasing ion energy, the damage depth is dependent on the angle of incident ion, the curves of the damage depth for Ga ion and As ion at 30 keV nearly superpose, while the damage depth for Ga with 90 keV ion is more than that for As ion with the same energy.
文摘Gaussian beam migration （GBM） is an effec- tive and robust depth seismic imaging method, which overcomes the disadvantage of Kirchhoff migration in imaging multiple arrivals and has no steep-dip limitation of one-way wave equation migration. However, its imaging quality depends on the initial beam parameters, which can make the beam width increase and wave-front spread with the propagation of the central ray, resulting in poor migration accuracy at depth, especially for exploration areas with complex geological structures. To address this problem, we present an adaptive focused beam method for shot-domain prestack depth migration. Using the infor- mation of the input smooth velocity field, we first derive an adaptive focused parameter, which makes a seismic beam focused along the whole central ray to enhance the wave- field construction accuracy in both the shallow and deep regions. Then we introduce this parameter into the GBM, which not only improves imaging quality of deep reflectors but also makes the shallow small-scale geological struc- tures well-defined. As well, using the amplitude-preserved extrapolation operator and deconvolution imaging condi- tion, the concept of amplitude-preserved imaging has been included in our method. Typical numerical examples and the field data processing results demonstrate the validity and adaptability of our method.
文摘Background:Enhanced depth-of-focus intraocular lenses(EDOF IOL)have filled the gap between monofocal and multifocal intraocular implants with optical qualities of monofocal lenses and usually minor dysphotopsias typical for multifocal lenses.The purpose of this study was to evaluate visual outcomes after bilateral implantation of a new EDOF IOL in patients with requirements for perfect near and intermediate vision.Methods:The study included 15 patients(29 eyes as one was amblyopic)with bilateral implantation of LUXSMART EDOF IOL(Bausch&Lomb)with a targeted myopia(between-0.25 and-0.50D)in both eyes.Monocular corrected and uncorrected visual acuity for far,intermediate and near as well as refractive outcomes were evaluated at 1,3,6 and 12 months after the surgery.Additionally,binocular visual acuity,contrast sensitivity and defocus curve were measured at the final follow-up visit.At 12 months’visit patients completed a questionnaire evaluating patient satisfaction,spectacle independence and presence of dysphotopsias.Results:Binocular uncorrected visual acuities at 12 month’s visit were 0.13±0.16,0.06±0.08,0.07±0.09 and 0.15±0.09 logMAR for far distance,80 cm,66 cm and 40 cm respectively.Corrected binocular visual acuities at 12 months were 0.00±0.00,0.05±0.07,0.05±0.06,0.13±0.16 respectively for distance,80 cm,66 cm and 40 cm.Automated refraction spherical equivalent at 12 months’visit stood at-0.70±0.48D,which was 0.46D less than calculated biometric target,however spherical equivalent of subjective refraction at 12 months equaled–0.49±0.46D,which was closer to preoperative biometric target.Defocus curve had gentle shape without peaks typical for monofocal IOLs.Binocular contrast sensitivity results were superior to average results for that age group and equaled 1.78±0.16 logMAR without correction and 1.81±0.13 logMAR with correction.Spectacle independence for near and intermediate distances was achieved in all patients and for far distance in 73.3%of patients.Burdensome dysphotopsias were not reported in any case.Conclusions:EDOF IOLs targeted bilaterally at low myopia can provide excellent near and intermediate visual acuity and independence of any optical correction in majority of cases.This approach can be used in selected patients who are focused on stationary activities.
